Studying subjective experience, apart from preformed self-rating questionnaires, has nearly vanished in psychiatry, partly due to reliability concerns. Recent research in early detection of schizophrenia has entailed an increasing interest in the subtle experiential anomalies that may assist in identifying the patients at risk of psychosis. Some of these anomalies are described in the Bonn Scale for the Assessment of Basic Symptoms (BSABS). We examined the reliability of this instrument. SAMPLING AND METHOD: 18 hospitalised patients accepted to participate in a psychopathological interview assessing BSABS items, affective and psychotic symptoms.